Tow target releasing device



Dec. 11, 1945. LE ROY s. JESSEN 2,390,538

TOW TARGET RELEASING DEVIC E Filed Oct. 6, 1944 5 Sheets-Sheet 1 INVENTOR. LE 1901 d. L/ESSEN I Patented Dec. 11, 1945 2,390,538 TOW TARGET RELEASYINGDEVICE V Le Roy S..Jessen, Dayton, Ohio 1 Application October 6, 1944, Serial No. 557,538 5 Claims. (crave-105.3

(Granted under the act of March 3, 1883, as

amend ejdApril 30, 1928; 370 0. G. 757) The invention described herein maybe manufactured: and used by .orfor the Government ior governmental purposes, without the payment to me of any royalty thereon.

This invention relates to tow targetreleasing ,devices in which a target is supported on the end ofa tow line, kept there for a time, then released atwill and replaced by another when the first has served its/purpose, all while 'the tow line remains fully extended.

- In this kind of device there is usually some form of obstruction at the free end of the cable which serves to arrest and retain the target anchor which would otherwise pass over the end of the cable, together with means Onthe target being sent, outto cause the first to be released.

An object of'this invention is to provide a simple, inexpensive and effective device whereby any one of a series of targets whichis being towed at the end of the tow line of a towing plane, may be released therefrom and dropped, after being subjectedto practice fire,the arrangement; being i such that upon launching Of any subsequent target, the impact of its arrival at. the end'of the cable always releases the anchor of the target which is to be dropped.

,.One of the difiiculties in a device of this character is that the tow line, due to its natural twisted construction, untwists under load, and retwists when the load is removed. Since the re,- sistance of the target may impose a load of approximately three hundred lbs. and .thecable in current use untwists approximately one turn per ft. per hundred 1b. load, a three thousand it. cable may untwist as much as nine thousand turns in the period of time which it takes to reel it out; It thecable is unreeled from the tow plane with .the first target attached thereto, and no provision .has been made to take care ofrthis condition, the entire assembly consisting of the target and its attaching means spin and gyrate extensively. A reversewcondition is, ofcourse, encountered as the cable is reeled back in, the retwisting being at times at such speed that an ordinary swivel cannot keep up with it, whereupon the entire releasing mechanism at the end of the cable beats the air,;whipping in a circle and endangering the tow plane itself. This trouble is particularly pronounced as thelast target "of a series isreleased from the end of the cableby sending out a re leasing weight which is much lighter than a complete target, thus suddenly greatly reducing the load on thecable. q i

It is thereiore another object of the invention provide the obstruction or anchor retaining means on the end of the cable with a swivel mechanism which can readily take care of any untwisting and retwisting condition which may occur with substantially no tendency to turn the target with it.

Inasmuch as the release of any one target from the end of the tow line is accomplished by the shock of arrival of the next target of the series,

it is appropriate that the unloading of the cable by the release of the one target should be exactly coincident with the loading of the cable by the arrival of. the next, for otherwise a. considerable turning of the swivel in one direction or the other may take place either because the loads of both targets are momentarily applied together or momentarily both removed.

It is therefore another object of the invention to so construct and arrange the anchor releasing mechanism thatremoval of the load of the released target is exactly coincident with the application of theloadof the arriving target.

Since the swiveling action must take place between the load and the cable, and the shock of receiving the load of one target arriving at the release mechanism of the other is considerable, it is another object of the invention to provide means for modifying the impact of the arriving target on the swivel. a

Other objects and advantages will become evident as the invention is further described with reference to the drawings, wherein:

Fig. 1 is a top plan view of the invention with one tow target attached.

Fig. 2 shows a second tow target arriving at the end of the tow line and releasing the first target. Fig. 3 is a longitudinal axial section through the target-retainer which contains the releasing mechanism. i V

Fig. 4 is a longitudinalwofi-center section through the anchor release the section being taken at 4-- 4 of Fig. 5.

Fig. 5' is an end view of the anchor release viewed from the right.

Fig. 6 shows a split weight which may be used instead 0f the regular anchor release for releasing the last target of a series.

Like reference characters refer to like parts throughout the several views. 7

Referring now to the drawings, a towing cable Illis unwound from a suitable reel in a towing lplanea Neither the towing plane nor the reel are shown, since they do not form any part of the invention. The free end of the cable 'lil is "securely clamped in aswivel unit l2 which is shown in detail in Fig. 3 and comprises an outer clamp- 7 target.

ing member [4 with conical bore and an inner clamping member I 6 in the form of a cone somewhat smaller than the bore, the cone having a longitudinal groove for the cable extending completely around the cone, the groove being less in depth than the diameter of the cable. The cone is rced i t dam in sta e b a 99 .1 p in 18, thereaction of which is taken by a threaded plug 26 which is screwed into the end of the outer clamping member I4.

At one end the inner race 22 of an antifriction bearing is supported by a hub of the plug gt while at the other end one member 24 of a thrust bearing is mounted on a hub of the cable clamping member I4. A swivel housing 25 surrounds the entire swivel mechanisnnthe forward end of the housing being completely closed by th'screw plug 28 except for the central, opening through lease 48. I

.Each tow target is. provided with a releasable anchor, which comprises a pair of bent arms .38 (see I). hinged together and to a link 40 by a hinge pint'42; the free ends of the arms being hinged by ipins 44 to the ears 46 of the anchor release "48 which is shown in detail in Figs. 4 and 5. A short length of shock cord 49 may advantageously be interposed between the link 40 and the target although 'ifdesired the link '40 and'the cord 49 may bothbe eliminated and the anchor arms 38 connected directly to the Referring to Figs. 4 and 5., an anchor release "43 has cylindrical body portion 50 with central opening 52" through which the cables l0 passes freely. 'I-"hefo'rward end-bf the anchor release is concave as; at 54 and the'rearward end: is correspondingly convex asatfli, l

finer-oer facilitate mounting the release 48 or nanchor as onithe came "l the releaseis.-

cliwded into; equal"halves on the line 58 and inches" scare provided to hold the halves together, one of the latches beihg'shown in longitudinal-section in Fig. 4 and both in the end view A latch 60 consists'o f a latch bar 62 ofrectangular cross section' with the for-ward; end rounded as at 64, the rounded end projecting throughthe concave surface 54; Two hookmembers 66 extend laterally fromthe bar 62- through slpts inthe'onehalf-into undercut pockets 1i] in the other half. Springs F-Z- normally hold he latches in thelocked position shown-until; the convex end 'of'theanchor release of'a target being sent out strikes the lfOllYlQGjd ends 640? the latch on the anchor release of-a target which is 'to be droppedfi Dowels 14 may be provided to maintain alignmentof one-hal-f of'the-release with fthe'other. 4 J H The two halves ofthe anchor release 48 are carried, one half on each bent arm-of the anchor S'Sja pair of the arms-being"provided-on each target, whereby the anch release on the: target bei gfa n h a y srl e a p rs h anchor release on the targetbeing dropped. However,

when the lasttarg et is to be released and there are nolmore targets available to be sent out," an abhor, elease which; s I 9? itaqhfiqi a a r, to the rcher x ar et, stis ni out torelease the last t'ar'g et. Onsuch a weight a 5 0 to. h degree and 9 the s m reason that the release 48 is conve at SE. A 1 The mechanism shown is operated substantially as follows:

The tow line In may preferably be reeled out with the first of the series of targets-attached as seen in Fig. 1, attachment being effected by bringing the two bent arms 38 of the anchor 36 1 together forward of the swivel unit I2 and latching the two halves of the anchor release 48 by V pressing them together around the cable.

When the first target has been subjected to nraqtice fire it is, ready to be dropped, and releasing is accomplished by bringing together the bent arms .18 of the anchor 36. of the next target and latching the two halves of theancho'r release 43 around the tow line 10, then allowing the relatively moving air to take'the target back until the convex end 56 of the second anchor-release 48 strikes the concave end 54 of the first and thus presses the projecting ends 64 of the latches E0 and allows the halves'of the anchor release 48 of the first target to separate, whereby the first target is dropped and the second takes its place.

The reason for making theforwa'rol' and rearwards ends of the split anchor release 48 respectively concave andconvex will be apparent from an inspection of Fig. 2, where it may be seen that a convex end 56 and a concave end 54 necessarily come together with the axis of "the two weights at a slight angle.

By appropriately proportion-mg the spring 1-2 in the latch'mechanism, the shock of engagement of the second anchor release 48 with the first may be. minimized. The inclusion of the "length of shock cable 749 further reduces the shock of en'- gagement.

Having described'niy ihvention, r clairhf 1 For 'us'ein releasably connecting atow target to the free end of a tow cable so that it maybe released by impact of a weightsent rear-ward on the tow cable, the imprlivement which consists of a target retainer carried: on the rear end of said cable, an anchor-securedto said target; said anchor comprising two curvedarms hinged together andsecu'red to the-target at one end, the

ing means onthe one -part; engag-i ngmeans on theiother-par-t for enga'ging-the'first said engaging means to latchthe two parts of the anchor-release together, and: a latch" operating part -at the forward end: of said anchor-release,adapted to -be engaged. by said-weight to disengage said latch, whereby said target is released -f rom-I saidcable.

.2. Eonu'se-in releasablyconnecting-atowfltarget to the free' end- "or a tow cable s that it may} be released loyimp'abt of alike targ et sen-t rearward on the tow cable, the irnprove rnent which-consists of a target-retainer carries onthe rearend'of said cable said; retainer fhaving an inner -palt clampedto said cableand an outer part which rotates freely on said inner part-,an anchor;isecured to saidl target, said anchor comprising-two curved; arms hinged'together and secured to the target at one end, the curved arms extending around the retainer beyond its forward end, an anchor-release in two parts adjacent the forward end of said retainer and hinged one part to each arm at the forward end of the arms, and a latch associated with said anchor-release, said latch comprising engaging means on the one part, engaging means on the other part for engaging the first said engaging means to latch the two parts of the anchor-release together around the cable, and a latch operating part at the forward end of said anchor-release, adapted to be engaged by said like target and unlatched, whereby the first said target is released from said cable.

3. For use in releasably connecting a tow target to the free end of a tow cable so that it may be released by impact of a like target sent rearward on the tow cable, the improvement which consists of a target retainer carried on the rear end of said cable said retainer having an' inner part clamped to said cable, a housing surrounding said inner part, and anti-friction bearings for rotation of said inner part within said housing, an anchor secured to said target, said anchor comprising two curved arms hinged together and secured to the target at one end, the curved arms extending around the retainer beyond its forward end, an anchor-release in two parts adjacent the forward end of said retainer and hinged one part to each arm at the forward ends of the arms, a latch within said anchor-release,-a latch operating part extending from the forward end of said anchorrelease, said latch comprising engaging means on the one part and engagingvmeans on the other part adapted to engage the first said engaging means to hold the parts of said anchor-release latched together around the cable, said operating part being adapted to be engaged by said like target, whereby the said two parts of said anchor release may separate and said target be released from said cable.

4. For use in releasably connecting a tow target to the free end of a tow cable so that it may be released by impact of a like target sent rearward on the tow cable, the improvement which consists of a target retainer carried on the rear end of said cable, an anchor secured to said target, said anchor comprising two curved arms hinged together and secured to the target at one end, the

curved arms extending around the retainer be yond it forward end, an anchor-release in two parts adapted to surround the cable adjacent the forward end of said retainer and hinged one part to each arm at the forward ends of the arms, the forward and rearward ends of said anchor-release being respectively concave and convex, whereby impact of one of said anchor releases is received uniformly by the other when their axes are at a slight angle one with the other, a latch associated with said anchor-release, said latch comprisin engaging means on the one part, engaging means on the other part for engaging the first said engaging means, and an operating part extending through the forward concave end of said anchorrelease, said latch being adapted to normally hold the parts of said anchor-release latched together around the cable, and said operating part being adapted to be engaged by said like target and the latching thereby unlatched, whereby the two parts of said anchor-release may separate and said target be released from said cable.

5. The structure defined in claim 4 with a short length of shock cable connecting the anchor to the target.

LE ROY S. JESSEN. 

